1. Field of the Invention
The present invention relates to lane keep control apparatus and method for an automotive vehicle which are capable of preventing a deviation of the vehicle from a traffic lane on which the vehicle is traveling when the vehicle is about to deviate from the traffic lane during the travel.
2. Description of the Related Art
A Japanese Patent Application First Publication No. Heisei 11-96497 published on Apr. 9, 1999 exemplifies a first previously proposed lane keep control apparatus. In the first previously proposed lane keep control apparatus, the control apparatus determines that the vehicle has a tendency of deviation of the traveled position of the vehicle from a traveling traffic lane and outputs the steering control torque having a magnitude for a vehicle driver to overcome easily in accordance with a lateral deviation of the traveling position with respect to a reference position of the vehicle traveling position through a steering actuator so that the deviation of the vehicle from the traffic lane is prevented. In addition, a Japanese Patent Application First Publication No. 2001-310719 published on Nov. 6, 2001 exemplifies a second previously proposed lane keep control apparatus for the automotive vehicle. In the second previously proposed lane keep control apparatus, a yaw moment in a direction to avoid the deviation from the traveling traffic lane is developed according to a difference in a braking force between front and left road wheels so as to prevent the vehicle from being deviated from the traffic lane in a case wherein the control apparatus determines that the vehicle has the tendency to be deviated from the traveling traffic lane.